1. Field of the Invention
Embodiments of the invention relate to a solar cell, and more particularly, to a solar cell having an improved electrode structure.
2. Description of the Related Art
Recently, as conventional energy resource such as petroleum and coal are expected to be exhausted and the environment is seriously polluted, significance of development in next-generation clean energy is increasing. Also, demand for renewable energy is increasing in the 21st century, and thus, interest in solar cells is also increasing. Solar cells do not pollute the environment, use a practically infinite energy resource, and can be used semi-permanently. Thus, solar cells are expected to be an energy source for solving future energy problems.
Solar cells can be largely classified into a crystalline silicon solar cell, a thin-film solar cell, and a dye-sensitized solar cell. The cost of the crystalline silicon solar cell has increased due to a short supply of a silicon raw material and a shortage of a silicon substrate induced by installing a large number of solar cell systems in recent years. For this reason, a thin-film silicon solar cell, a dye-sensitized solar cell, and a plastic solar cell are in the spotlight because their cost is low, their consumption of the raw material is less, and their supply of the raw material is stable. Despite the low cost, however, low conversion efficiency and short lifetime of the solar cells, such as the thin-film silicon solar cell, the dye-sensitized solar cell, and the plastic solar cell, are blocking the industrialization thereof. Therefore, recent studies about the solar cells are focused on techniques for improving the efficiency of the solar cells. To improve the efficiency of the solar cells, a structure or a pattern of a front electrode formed on a light incident surface of the solar cell needs to be improved.